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Glassner A.S. Principles of Digital Image Synthesis

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Glassner A.S. Principles of Digital Image Synthesis
Издательство Springer, 1995, -1510 pp.
Two volumes
Inspiration begins with imagination and the spirit to create. Then comes the need to communicate, to share an idea or thought. Grab a pencil and you can make it real: a picture, abstraction made concrete, ideas preserved in time. Our hearts and minds are moved to tell stories, to teach what we think and feel to others and learn the same from them.
Of all the visual media, computer graphics is one of the newest. The computer is a powerful amplifier-it can take terse descriptions of the world and create pictures of that world, using any rules you choose. If we choose the classical rules of light, then we can make pictures that can pass for photographs; other rules explore other ways of seeing.
The field of image synthesis, also called rendering, is a field of transformation: it turns the rules of geometry and physics into pictures that mean something to people. To accomplish this feat, the person who writes the programs needs to understand and weave together a rich variety of knowledge from math, physics, art, psychology, physiology, and computer science. Thrown together, these disciplines seem hardly related. Arranged and orchestrated by the creator of image synthesis programs, they become part of a cohesive, dynamic whole. Like cooperative members of any complex group, these fields interact in our minds in rich and stimulating ways. I find each of these disciplines inherently interesting; together they are fascinating. Understanding the interplay of such diversity and exploring the connections is exciting, and with the understanding of such elegant ideas comes a deep satisfaction. That's why I love computer graphics: it's stimulating to the intellect and rewarding to the heart.
I couldn't find a book that presented image synthesis as a complete and integrated field of study, encompassing all of the topics I just mentioned. But I love to write. And so this book was born. .
The big idea in this book is to layout the rules that tell a computer how to take 3D shapes and lights and create a picture-one that would pass for a photograph of that scene if it existed. So our driving problem is the simulation of Nature's illumination of a scene, the capturing of that illumination on film, and its presentation to an observer. Sometimes we bypass the film idea and just imagine an observer in the scene. We often make it easy and pretend the observer has only one eye, so we can ask, "Given this scene, what picture do I show to the observer to make her think that she's viewing the real scene?" We use all the disciplines I listed earlier to answer this question, since our goal is not merely to create an image, but to create a perceptual response in the viewer.
It's all a trick! Like any visual medium, computer graphics creates illusions. Fred Brooks [65] has observed that our job as image synthesists is to create an illusion of reality-to make a picture that carries our message, not necessarily one that matches some objective standard. It's a creative job.
This book is not about how to write specific programs, or how to implement particular algorithms. The history of computer graphics is like any discipline of thought: tried-and-true ideas are constantly challenged by new ideas, and sometimes the older ones, once seemingly invulnerable, are found somehow deficient and fade away. So it is with rendering algorithms; our marketplace of ideas is a noisy and bustling place right now.
But there are some ideas that I believe are fundamental, that come from the basis of our discipline and lie at the heart of all we do. Those are the ideas in this book. I have included many examples from current practice, but I rarely go into their details. There are lots of references, and you can find a wealth of implementation information in the literature. My purpose here is to discuss the underlying principles-the ideas that have slowly emerged as the core of our discipline.
There are three such basic fields: human vision, signal processing, and physics. These are not independent disciplines; as I've said, much of the fun of image synthesis is seeing how these fields fit together. But here I have chosen to give each of these topics its own day on the stage, in the form of a unit of the book. The fourth unit pulls the first three topics together and shows how they combine to make rendering algorithms. I look at two of today's most popular techniques, hierarchical radiosity and distribution ray tracing, as examples to illustrate the principles. Finally, the fifth unit contains several appendices with short topic summaries, historical notes, and reference data.
I make a general argument in this book. To design and implement a computer system for creating synthetic digital images for people to view, you need to understand the physics of the world you are simulating, the appropriate methods for simulating those physics in the computer, and the nature of the human visual system that ultimately interprets the image.
The following few paragraphs describe the structure of the book and show how the discussion has been arranged to provide an accumulating body of mathematical, physical, and physiological information that culminates in a modern image rendering system. There's too much information here for a one-semester course on image synthesis. Teachers may choose to present in detail only some of the information in this book, covering the rest at a higher level; deciding where to dig deeply and where to summarize lightly will depend on the instructor, the course, and the students. The only material that ought not be skipped is the section on notation in Chapter
4. With suitable summaries from the instructor to cover the gaps, students can work sequentially, skipping material as desired. Since the book is cumulative, I don't recommend hopping back and forth.
Volume I
Unit I The Human Visual System and Color
The Human Visual System
Color Spaces
Unit II Signal Processing
Signals and Systems
Fourier Transforms
Wavelet Transforms
Monte Carlo Integration
Uniform Sampling and Reconstruction
Nonuniform Sampling and Reconstruction
Sampling and Reconstruction Techniques
Volume II
Unit III Matter and Energy
Energy Transport
Integral Equations
The Radiance Equation
Unit IV Rendering
Ray Tracing
Rendering and Images
The Future
Unit V Appendices
A Linear Algebra
B Probability
C Historical Notes
D Analytic Form Factors
E Constants and Units
F Luminaire Standards
G Reference Data
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